Applying double-mass pendulum oscillator with tunable ultra-low frequency in wave energy converters

Qinlin Cai and Songye Zhu

Applied Energy, 2021, vol. 298, issue C, No S0306261921006504

Abstract: Ocean waves are an ultra-low-frequency renewable energy source. Various point absorbers have been developed over the past decades as small-sized wave energy converters (WECs). However, realizing tunable and ultra-low frequencies in WECs remains an extremely challenging technological issue. This paper proposes a novel and simple design of a double-mass pendulum (DMP) oscillator whose natural frequency can be conveniently tuned by simply adjusting the positions of two independent masses. Shake table test results successfully illustrated that the tunable ultra-low natural frequency range (0.2–1.4 Hz) can be achieved even in a small-size DMP prototype, which can be hardly achieved in conventional oscillator designs. Subsequently, a small prototype of a point absorber enclosing the DMP-based energy harvester was fabricated and tested in a wave flume under different wave heights and periods. Average output power of nearly 100mW was captured in the experimental case when the wave period and height were 0.7 s and 0.1 m, respectively. The corresponding power extraction in a large-scale case is predicted to be up to 3.5 kW under wave height of 2 m and wave period of 6 s. The experimental results demonstrated that the proposed DMP oscillator is a promising power extraction device with an appealing tunable ultra-low frequency, which is extremely suitable for WECs, as well as other energy harvesters designed for ultra-low-frequency vibration sources.

Keywords: Double-mass pendulum; Wave energy converter; Frequency tuning; Ultra-low frequency; Renewable energy (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261921006504
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:298:y:2021:i:c:s0306261921006504

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2021.117228

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().